title: Heterogeneity in nanoparticles influences biodistribution and targeting.
abstract: OBJECTIVE
  A large fraction of the administered dose of nanoparticles (NPs) localizes into nontarget tissue, which could be due to the heterogeneous population of NPs.
  
  
  METHODS
  To investigate the impact of the above issue, we simultaneously tracked the biodistribution using optical imaging of two different sized poly(d,l-lactide co-glycolide) NPs, which also varied in their surface charge and texture, in a prostate tumor xenograft mouse model.
  
  
  RESULTS
  Although formulated using the same polymer and emulsifier concentration, small NPs were neutral (S-neutral-NPs), whereas large NPs were anionic (L-anionic-NPs). Simultaneous injection of these NPs, representing heterogeneity, shows significantly different biodistribution. S-neutral-NPs demonstrated longer circulation time than L-anionic-NPs (t1/2 = 96 vs 13 min); accounted for 75% of total NPs accumulated in the tumor; and showed 13-fold greater tumor to liver signal intensity ratio than L-anionic-NPs.
  
  
  CONCLUSIONS
  The data underscore the importance of formulating nanocarriers of specific properties to enhance their targeting efficacy.
authors.affiliation: Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44106, USA.
authors.forename: Isaac M
authors.initials: IM
authors.lastname: Adjei
authors.forename: Chiranjeevi
authors.initials: C
authors.lastname: Peetla
authors.forename: Vinod
authors.initials: V
authors.lastname: Labhasetwar
mesh_terms: D000818:Animals; D064593:Heterografts; D008297:Male; D051379:Mice; D053758:Nanoparticles; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology; D019265:Spectroscopy, Near-Infrared; D014018:Tissue Distribution